Nahj al-Balāgha

Hadith 220
warfare-jihadimam-aliahl-al-bayt
ومن كلام له (عليه السلام) وقد استبطأ أصحابه إذنه لهم في القتال بصفين
When Amīr al-mu’minīn’s men showed impatience on his delay in giving them permission to fight in Ṣiffīn, he said:
Source: al-Sharīf al-Raḍī